Description from Knitty.com:

This handbag uses Lamb’s Pride by Brown Sheep, a wool/mohair blend. It is a heavier worsted weight yarn, and the mohair lends a pleasing sheen and softness to the final bag. The slip stitch patterns add further rigidity to the final fabric, so you actually CAN make a sturdy bag that sits up on its own with only one strand of yarn.

It is easy to change the dimensions of the bag by adding or subtracting groups of 8 stitches when you cast on, or groups of 16 rows as you knit the base. Then simply make the bag as tall as you like by adding additional solid and multi-color rounds.